/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.rest.messages.job.metrics;

import org.apache.flink.runtime.rest.messages.ConversionException;
import org.apache.flink.runtime.rest.messages.MessageQueryParameter;
import org.apache.flink.util.StringUtils;

import java.util.Locale;

/**
 * TODO: add javadoc.
 */
public class MetricsAggregationParameter extends MessageQueryParameter<MetricsAggregationParameter.AggregationMode> {

	protected MetricsAggregationParameter() {
		super("agg", MessageParameterRequisiteness.OPTIONAL);
	}

	@Override
	public AggregationMode convertStringToValue(String value) throws ConversionException {
		try {
			return AggregationMode.valueOf(value.toUpperCase(Locale.ROOT));
		} catch (IllegalArgumentException iae) {
			throw new ConversionException("Not a valid aggregation: " + value, iae);
		}
	}

	@Override
	public String convertValueToString(AggregationMode value) {
		return value.name().toLowerCase();
	}

	@Override
	public String getDescription() {
		return "Comma-separated list of aggregation modes which should be calculated. " +
			"Available aggregations are: " + StringUtils.toQuotedListString(AggregationMode.values()) + '.';
	}

	/**
	 * The available aggregations.
	 */
	public enum AggregationMode {
		MIN,
		MAX,
		SUM,
		AVG
	}
}
